I updated my ST2 2 days ago, but when I ran the update I can't open ST2 at all. When I try open it through terminal I get this message:/usr/bin/sublime-text-2: line 2: 3823 Segmentation fault /usr/lib/sublime-text-2/sublime_text $*

Neither the current regular build nor the current dev build have this problem - it sounds like you're using an old dev build. I don't know the details with the PPA you're using, but if you use the version from sublimetext.com/2 it'll run for you.